Surprise! No UV-B (UVB=Vitamin D or D3) in Vancouver winter sunlight

[BOMBOVA]

i have two calibrated UV detectors, mid UV, and Deep UV capable, " selective filters over the detector " and as you say, the levels of UV , at this time of the weather pattern is very low, just detectable on my mid range sensitivity, and at a quarter candle in what seems direct sunlight "" I do suspect that ice crystals in wispy cirus clouds is impeding deep UV Most likely a combination of air born particulates. bottom line the uv at the moment is very low indeed.